This invention relates generally to rotary machines and more particularly, to methods and apparatus for assembling and operating wind turbine nacelles.
At least some known wind turbine generators (“wind turbines”) include a rotor having multiple blades. The blades are coupled to a rotatable hub to facilitate transforming mechanical wind energy into a mechanical rotational torque that drives one or more generators. Although some known wind turbines include gearless direct drive generators, known wind turbines generally include generators that are rotationally coupled to the rotor through a gearbox. The gearbox facilitates increasing an inherently low rotational speed of the turbine rotor. The generator uses the rotational speed to facilitate efficiently converting the rotational mechanical energy to electrical energy, which is fed into a utility grid.
In known wind turbines including a gearbox, the rotor, generator, gearbox and other wind turbine components are typically mounted on a load-bearing bed frame within a housing, or nacelle that is positioned on top of a base that may be a truss or tubular tower. Because the wind turbine components are mounted on the load-bearing bed frame, an outer shell or external skin of the nacelle serves as a non-load bearing protective skin that may be formed as a heavy casting. Therefore, some known nacelle configurations introduce substantial weight at the top of the wind turbine tower to facilitate supporting the wind turbine components positioned within. Further, any associated component supporting features of some known nacelles also facilitate increasing weight at the top of the wind turbine tower. As a result of increased weight, some known nacelles facilitate increasing capital and operational costs of the wind turbine.